In recent years, medical materials utilizing various polymer materials have been studied, and they are expected to be used for membranes for artificial kidneys, membranes for plasma skimming, catheters, stents, membranes for artificial lungs, artificial blood vessels, anti-adhesion membranes, artificial skins, and the like. In these materials, a synthetic polymer material, which is an xenobiotic substance, is used in contact with a biological tissue or a body fluid such as blood. Therefore, such a medical material is required to be biocompatible. The biocompatibility required for a medical material varies depending on its purpose and usage. A medical material used as a material that contacts blood is required to have characteristics of inhibiting the blood coagulation system, inhibiting the adhesion/activation of platelets, and inhibiting the activation of the complement system (antithrombogenicity).
Usually, a medical device is made antithrombogenic by a method in which the substrate forming the medical device is covered with an antithrombogenic material, or a method in which an antithrombogenic material is fixed to the surface of the substrate.
For example, JP-A-4-152952 discloses a membrane for an artificial organ or a medical device, having on the surface thereof a synthetic polymer that simultaneously satisfies biocompatibilities of inhibiting the adhesion/activation of platelets, an inhibitory effect on the activation of the complement system, and affinity with in-vivo tissues. In addition, U.S. Patent Application No. 2008/0262181 (corresponding to WO 2005/113620) discloses a biocompatible material containing a homopolymer or copolymer that has reduced interaction with biological components such as proteins and blood cells and is highly biocompatible.